High tension cut-out



7 A ril 17, 1934. R s v wow 1,955,571

HIGH TENSION CUT-OUT Filed April- 3, 1933 Patented Apr. 17, 1934 HIGHTENSION OUT-OUT Reginald S. V. Wood, Denver, Colo. Application April 3,1933, Serial No. 664,068

4Claims.

This invention relates to improvements in vaporsign constructions andhas reference more particularly to an electric circuit comprising anumber of neon tubes in series and of a high potential cut-out is to beused in parallel with each of the sign sections.

It is well known that display signs for outdoor advertising are .nowusing almost exclusively neon tubes for the production of light forillumination as such signs possess advantages that are not possessed bythe ordinary incandescent lamp illaminated signs and can be operated ata greatly decreased expense.

Neon vapor tubes are operated on a high potential alternating currentcircuit and take comparatively small amounts of .current, but theordinary voltage employed in connection with such signs is fifteenthousand volts and therefore if a break occurs in the circuit, this highpotential current may cause considerable damage and set fire to thesigns and to the buildings to which they are connected, as well asdestroy other sections of the vapor tubes.

When an ordinary neon sign comprising several sections, as, for example,several letters, each formed from a separate section of tubing and inwhich the sections are all connected in series, has abreak occur in oneof the sections, the entire sign goes out and the trouble man hasconsiderable difilculty in determining which of the several sections isdefective because since all the letters are connected in series, theywill all go out when one becomes defective.

It is the object of this invention to produce a simple and efilcienthigh potential cut-out that can be connected in parallel with eachsection and which shall be so constructed that as long as the section towhich it is connected functions properly, the cut-out circuit will beheld in open position, but if the section with which it is connectedbreaks'or ceases to function properly, the voltage across the terminalsof this section will immediatelyrise and will cause an arc to take placein the cut-out, thereby releasing a contact member which completes acircuit between the terminals, thereby permitting the remaining portionsof the sign to function.

The transformers employed in connection with signs of this type areconstructed with high potential and low current secondaries and thesecondary winding is usually so designed that it has sufllcientimpedance to prevent it from burning out, even when the terminals areshort circuited, and therefore in a sign composed of several sections orletters, all but one of the letters can be short circuited and theremaining letter will still be illuminated without any damage to it onaccount of the increased voltage.

In order to more clearly describe this invention, reference will be hadto the accompanying drawing in which it has been illustrated, and inwhich:

Fig, 1 is a circuit diagram showing my combination applied to a neonsign;

Fig. 2 is a longitudinal section through one of 66 the high potentialcut-out devices showing the same in open circuit position;

Fig. 3 is a section similar to that shown in Fig.

2, but shows the cut-out in closed circuit position, as it appears afterit has operated to short circuit 70 one of the sign sections;-

Fig. 4 is a section taken on line 44, Fig. 2, and shows the manner inwhich one of the contact members is held out of engagement with theother; and 7 Fig. 5 is a section similar to that in Fig. 4, but showsthe parts in the position they assume after the fusible supportingmember has been destroyed by heat.

In the drawing reference numeral 1 indicates go a generator andreference numeral 2 the primary of a high tensioned transformer, whilereference numeral 3 indicates the secondary of the trans former.Extending from the terminals of the secondary coil of the transformerare conductors 5 4 and 5.

Conductor 4 is connected to a terminal 6 at one end of an electric signcomprising the letters 7, 8 and 9, while the conductor 5 is connected tothe terminal 10 at the other end of the sign. The several sign sections,which have been shown as comprising the three capital letters "A A M,are connected in series. Normally, the sign would operate in the mannershown without any means for short circuiting any of the letters in casethat section of the tube or sign should break. In the ordinary way, ifone of the sections becomes inoperative, all of the letters willimmediately cease to function with the result that the sign becomesuseless until it has been re- 00 paired, and owing to the fact that allof the let ters are dark, the repair man must resort to an elaboratesystem of testing before he can find out which letter is defective. Whena neon sign of the ordinary construction becomes defective, the highpotential from the secondary winding will try to overcome the insulationand unless the parts are sufliciently insulated to resist the entiresecondary voltage, it will jump across to some 110 other part of thesign and sometimes fires will be started in this manner, while at othertimes different sections of the sign will be ruined by the highpotential thus released.

It is the object of this invention to connect in parallel with each signsection, a high potential cut-out device that will short circuit thesection with which it is connected whenever the voltage across theterminal rises unduly, as it always does when the tube is injured so asto destroy the vacuum.

The construction of the cut-out device has been shown in Figs. 2, 3, 4and 5 from which it will be seen that it consists of a tube ofinsulating material 11 which may be of glass or other insulatingmaterial, but which is preferably constructed of glass. The tube mayhave a length of about from two to three inches, although lengths inexcess of this may be used. When the tube is made of glass, twodiametrically located projections 12 are provided near one end and ashort piece of readily fusible material 13 is placed with its ends inthe recesses on the inside of the tube, as shown in Fig. 4. At one endof the tube a conductor 14 is provided. This conductor terminatesapproximately below the fusible element 13, as shown in Fig. 2 and isheld in place by a plug 15, which may be of cork or other suitablematerial. The inner end of the conductor 14 is convex on its uppersurface, as designated by reference numeral 16, while the other end isbent as shown in Fig. 2, so as to form two parallel sides 17 and 18between which the ends of a conductor 19 can be placed. Extendinginward- 1y from the other end of the tube, is a conductor having astraight portion 20 that is held in place by means of a plug 15.Directly inside of the plug, the conductor is preferably bent back andforth as indicated by reference numeral 21 so as to give it a springeffect, and this conductor then extends over onto the fusible member 13,and is supported on the latter as shown in Fig. 2. A conductor 19extending from the other terminal of the tubular section is connected tothe bent end portions 17 and 18 of conductor 20. It will be seen thatwhen the parts are in the position shown in Fig. 2, there is a gapbetween conductors 16 and 20 and that therefore no current can flowthrough this bypass. If, however, the tube section 7 should spring aleak so as to destroy the vacuum, the amount of voltage necessary tosend a current through the tube would immediately increase to such anextent that an arc would be set up between the two conductors located inthe tube 11 and the heat from this are would melt the fusible wire andpermit the conductor 20 to snap down into contact with the convex end 16of conductor 14, as shown in Figs. 3 and 4. A short circuit will now beestablished between the two terminals 6 and 6 and therefore the currentwill still flow through letters 8 and 9 and when the repair man arrives,he can immediately see which letter is out of commission.

It is evident that the cut-out functions in the same way regardless ofwhich letter or section goes out of commission and that therefore onlythe defective section will be eliminated and therefore when a sign isequipped with this high potential cutout it will continue to functionexcept with respect to the defective section.

Having described the invention what is claimed as new is:

1. A high tension cut-out for use in short-circuiting, a high tensionapparatus comprising in combination, a tubular member of insulatingmaterial, an electrical conductor extending inwardly from each endthereof, one of said conductors being resilient, the adjacent ends ofthe conductors overlapping, means at each end of the tube for attachingthe conductors to the tube, the resilient conductor functioning as ameans for urging the adjacent ends of the conductors into electricalengagement, and means for holding the conductors in spaced relation,said means comprising a link of fusible material extending transverselyacross the interior of the tube with its ends secured to the wall of thelatter, the link serving as a support for one of the resilientconductors.

2. A high tension cut-out for use in short-circuiting, a high tensionapparatus comprising, in combination, a tubular member of insulatingmaterial, an electrical conductor extending inwardly from each endthereof, one of said conductors being resilient, the adjacent ends ofthe conductors overlapping, means at each end of the tube for attachingthe conductors to the tube, the resilient conductor functioning as ameans for urging the adjacent ends of the conductors into electricalengagement, the inner surface of the tube having oppositely locateddepressions, and a link of readily fusible material having its endslocated in the depressions, said link serving to support the resilientconductor out of engagement with the other in opposition to theresilient force tending to move them into engagement.

3. A high tension cut-out for use in short-circuiting, a high tensionapparatus comprising, in combination, a tubular member of insulatingmaterial, an electrical conductor extending inwardly from each endthereof, one of said conductors being resilient, the adjacent ends ofthe conduc tors overlapping, means comprising removable plugs in theends of the tube for attaching the conductors thereto, the resilientconductor func tioning as a means for urging the adjacent ends of theconductors into electrical engagement, and means for holding theconductors in spaced relation, said means comprising a link of fusiblematerial extending transversely across the interior of the tube with itsends secured to the wall of the latter, the link serving as a supportfor the resilient conductor.

4. A short circuiting device for the purpose described comprising, incombination, a tubular member of insulating material, an electricalconductor projecting inwardly into the tube from each end thereof, aremovable plug at each end of the tube for holding the conductors inplace, the ends of the conductors overlapping within the tube the upperconductor being resilient and biased towards the lower conductor, so asto normally hold the conductors in electrical contact, the ends of theconductors outside of the tube having means for making connection withelectrical conductors, and a fusible link connected with the inside ofthe tubular member and with the resilient upper conductor to hold thelatter in open circuit position and to permit it to move to circuitclosing position when the fusible link melts.

REGINALD S. V. WOOD.

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